Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K15/00—Anti-oxidant compositions; Compositions inhibiting chemical change
  • C09K15/04—Anti-oxidant compositions; Compositions inhibiting chemical change containing organic compounds
  • C09K15/30—Anti-oxidant compositions; Compositions inhibiting chemical change containing organic compounds containing heterocyclic ring with at least one nitrogen atom as ring member
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07B—GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR
  • C07B63/00—Purification; Separation; Stabilisation; Use of additives
  • C07B63/04—Use of additives
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
  • C07C51/42—Separation; Purification; Stabilisation; Use of additives
  • C07C51/50—Use of additives, e.g. for stabilisation
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C67/00—Preparation of carboxylic acid esters
  • C07C67/48—Separation; Purification; Stabilisation; Use of additives
  • C07C67/62—Use of additives, e.g. for stabilisation

Definitions

• the present invention relates to a process for the chemical and/or physical treatment of mixtures which contain at least one chemical compound having at least one ethylenically unsaturated group.
• Chemical compounds which contain at least one ethylenically unsaturated group are generally known and are important starting compounds for the preparation of polymers (for example by free radical polymerization) which are used, inter alia, as adhesives or as binders.
• (meth)acrylic acid (“(meth)acryl-” is used in this publication as an abbreviation for “acryl- or methacryl-”)
• esters of (meth)acrylic acid, nitrites of (meth)acrylic acid or styrene it is constantly necessary to subject mixtures which contain at least one monomer to chemical and/or physical treatments in a manner known per se.
• esterification of (meth)acrylic acid with monohydric or polyhydric alkanols cf. for example EP-A 463 434
• treatment of (meth)acrylic acid-containing mixtures by rectification cf. for example DE-A 19 810 962 or EP-A 648 732
• DE-A 19 810 962 or EP-A 648 732 may be mentioned by way of example.
• suitable alkali metals X are in particular Na and K.
• R 1 , R 2 , R 3 and R 4 independently of one another, may be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl or tert-butyl. Accordingly, compounds (I) and (II) in which all radicals R 1 , R 2 , R 3 and R 4 are methyl or in which all radicals R 1 , R 2 , R 3 and R 4 are ethyl are also suitable according to the invention.
• R 5 may be, inter alia, C 15 - to C 25 -alkyl or C 17 - to C 22 -alkyl.
• the corresponding alkylsuccinic anhydrides can be reacted with 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (HTEMPO) at from 60 to 120° C.
• HTEMPO 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl
• the anhydride: N-oxyl molar ratio chosen for this purpose is from 0.8:1 to 1.5:1.
• the reaction is carried out in the absence of a solvent.
• suitable ones are, for example, aromatic and/or aliphatic hydrocarbons, such as toluene, xylene and cyclohexane, as well as diphenyl ether, dialkyl phthalates, dialkylacetamides and N-alkylpyrrolidones.
• the reaction time is as a rule 0.1-5 hours.
• the synthesis is advantageously carried out under anhydrous conditions.
• the alkylsuccinic anhydrides used may be, for example, compounds such as tetrapropenylsuccinic anhydride (e.g. GP 103 from CONDEA), n-alkenylsuccinic anhydride having a number average molecular weight (M n ) of about 520 (e.g. GP 104 from CONDEA), or polyisobutenylsuccinic anhydride having an M n of about 850 (e.g. GP 105 from CONDEA) or having an M n of about 1400 (e.g. GP 106 from CONDEA).
• tetrapropenylsuccinic anhydride e.g. GP 103 from CONDEA
• n-alkenylsuccinic anhydride having a number average molecular weight (M n ) of about 520 e.g. GP 104 from CONDEA
• possible compounds having at least one ethylenically unsaturated group may be, for example, styrene, butadiene, ethylene, vinyl ethers, vinyl esters, acrylic acid, methacrylic acid, alkyl esters (in particular C 1 - to C 8 -alkyl) of acrylic acid and methacrylic acid, methacrylonitrile, acrylonitrile or N-vinylpyrrolidone.
• the compounds I and II to be used concomitantly according to the invention are employed as a rule in amounts of from 50 to 1000 ppm by weight, based on the amount of the monomers contained in the mixture to be treated according to the invention.
• the amount used may however also be up to 2000 or up to 3000 ppm by weight, on a corresponding basis. In suitable cases, however, it is of course also possible to use less than 50 ppm by weight.
• the compounds (I) and (II) to be used according to the invention are preferably chosen so that, when used in the required amount, they are soluble in the mixture to be treated according to the invention.
• mixtures of compounds I and II are generally used.
• the compounds I and II can be used in the novel processes also as a mixture with other, known polymerization inhibitors and/or antifouling compositions.
• Suitable substances of this type include air, hydroquinone, hydroquinone monoethyl ether (MEHQ), paranitrosophenol, paramethoxyphenol, phenothiazine (PTZ), phenylenediamines, 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (HTEMPO), organic sulfonic acids (for example those published in EP-A 648 732), surfactants (for example those mentioned in DE-A 19810962) and all polymerization inhibitors stated in WO 9921893.
• MEHQ hydroquinone monoethyl ether
• PTZ paranitrosophenol
• HTEMPO 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl
• organic sulfonic acids for example those published in EP-A 648 7
• the novel chemical treatment may be, for example, a conventional chemical reaction of a monomer with retention of the at least one ethylenically unsaturated group.
• the esterification of, for example, (meth)acrylic acid with alkanols has already been mentioned as an example.
• the novel physical treatment may be, for example, an extraction, distillation, rectification, absorption or crystallization process.
• the mixtures to be treated according to the invention may be, for example, pure monomer mixtures as well as mixtures of monomers and of substances other than monomers.
• the weight fraction of the monomers in the mixtures to be treated according to the invention is at least 5 or at least 10 or at least 15 or 25 or 40% by weight.
• the mixture to be treated according to the invention may comprise ⁇ 95% by weight of (meth)acrylic acid.
• the novel process is suitable, inter alia, for isolating, by rectification, (meth)acrylic acid from a mixture containing, as main components, (meth)acrylic acid and an organic liquid having a higher boiling point than (meth)acrylic acid, as described in DE-A 19810962.
• the compounds I and II to be used according to the invention can be fed to the isolation by rectification at all points where WO 9921893 recommends the addition of a surfactant. If required, they can be used together with surfactants. Frequently, the compounds I and II are added in solution in (meth)acrylic acid.
• novel procedure is also suitable in the case of the processes for the purification of crude (meth)acrylic acid by distillation, as described in EP-A 35 648 732.
• the compounds I and II to be used according to the invention can be employed alternatively to or together with the sulfonic acids and polymerization inhibitors used in EP-A 648 732.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Materials Engineering (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Hydrogenated Pyridines (AREA)

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Cited By (2)

Citations (9)

• 1999
  • 1999-10-05 DE DE19947868A patent/DE19947868A1/de not_active Withdrawn
• 2000
  • 2000-10-02 BR BR0014495-9A patent/BR0014495A/pt not_active IP Right Cessation
  • 2000-10-02 DE DE50006621T patent/DE50006621D1/de not_active Expired - Lifetime
  • 2000-10-02 EP EP00969378A patent/EP1218320B1/de not_active Expired - Lifetime
  • 2000-10-02 WO PCT/EP2000/009630 patent/WO2001025173A1/de active IP Right Grant
  • 2000-10-02 US US10/089,065 patent/US6849758B1/en not_active Expired - Fee Related

Patent Citations (9)

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